Introduce Flow table test. How can sulphate attack be controlled?
Flow Table Test:-
This is a laboratory test, which gives an indication of the quality of concrete with respect to consistency, cohesiveness and the proneness to segregation. In this test, a standard mass of concrete is subjecting to jolting. The spread or the flow of the concrete is measured and this flow is related to workability.
Sulphate attack can be controlled by:
Short notes on :
Explain Kelly Ball to measure the workability of concrete. Mention the limitation of the test.
Differentiate between creep and shrinkage of concrete.
What are flaky and elongated aggregates? How can the shape of aggregate influence strength of concrete? Following is the result of a sieve analysis of 500 gm aggregate:
|IS sieve size||10 mm||4.75 mm||2·36 mm||1·18 mm||600 micron||300 micron||150 micron||lower than 150 micron|
|Weight retained in gm||0||10||50||50||95||175||85||35|
Find out the 'Fineness Modulus' of the sample
Design concrete mixes of M30 to suit the following data per IS:10262-1982 :
Characteristic cube strength = M-30, type of cement - ordinary Portland, fine aggregate natural river sand conforming to grading zone II of table-4 of IS:383-1970 coarse aggregate-crushed (angular) coarse aggregate of 20 mm maximum size conforming to IS:383 code requirements, specific gravities of cement, sand and coarse aggregate are 3·14, 2·63 and 2·61 respectively. Type of exposure - mild, Degree of quality control - very good. Degree of workability = 0·08. use IS:10262-1982.